AT THEIR RESPECTIVE conventions over the past fortnight, warring Democrats and Republicans agreed on their determination to administer bitter medicine to the American people. “The work ahead will be hard,” vowed Rep. Paul Ryan, the Republican vice-presidential nominee. “I won’t pretend the path I’m offering is quick or easy,” Mr. Obama chimed in.

But as the dust settled over Tampa and Charlotte and we tried in vain to recall a single hard truth any of the candidates had told us, it occurred to us that maybe they were stressing their supposed courage to distract us from their true point of convergence: their mutual, utter and utterly depressing failure to grapple honestly with the nation’s biggest problem.

That problem is the nation’s debt. We say so not because we think budgets matter more than anything else but because nothing else — nothing that really matters to people — will be unaffected if the nation does not get its long-term finances in order. The classroom overcrowding Mr. Obama promised to ease? The military Mitt Romney vowed to strengthen? Neither can happen if entitlement programs and interest on the debt consume every dollar of revenue — but that’s what will happen by 2025 on the current path, according to the Congressional Budget Office. By 2055 interest payments alone would eat up the totality of revenue.

It’s heartening, on one hand, to realize how fixable the problem is. Modest tax increases and challenging but manageable adjustments to Social Security and Medicare could buy a lot of time. Confidence would return, and along with it economic growth, which is what the country needs most of all. The United States is in a better position to handle the challenge than most developed countries. But that advantage will dissipate if the political system does not rise to the task.

Mr. Romney professes to care deeply about the debt. But his tax cuts would cause more of it. He promises to counter them by limiting deductions and loopholes, but which ones and by how much? Mortgage interest? Charitable giving? He won't say.

He promises also to ”fundamentally reduce the size of government,” as New Jersey Gov. Chris Christie boasted at the GOP convention. Mr. Romney’s brave, sacrificial offering: the National Endowment for the Arts, less than a fingernail’s worth of the federal budget.

Mr. Obama says that he cares, too. He will take “responsible steps to strengthen” Social Security. Which steps? Raising the retirement age? Slowing cost-of-living adjustments? He doesn’t say. He will save Medicare by controlling health-care costs. How, since he ruled out Mr. Ryan’s competition-driven plan? He won’t say.

“You didn’t elect me to tell you what you wanted to hear,” Mr. Obama said in his acceptance speech. “You elected me to tell you the truth.” Mr. Christie said, “We believe in telling hardworking families the truth about our country’s fiscal realities.”

With less than two months before the election, is there any hope of hearing fiscal truth from either candidate? Can reporters press harder for answers, or can debate questioners? Given their shared reticence, Mr. Obama and Mr. Romney may have an inclination not to press each other for honest answers about their plans. Maybe such fudging is tactically sound. The country, though, deserves better.